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Date:      Mon, 16 Jul 2001 10:41:55 -0400 (EDT)
From:      Kenneth Wayne Culver <culverk@wam.umd.edu>
To:        Luigi Rizzo <luigi@info.iet.unipi.it>
Cc:        Tim <tim@futuresouth.com>, Matt Dillon <dillon@earth.backplane.com>, Leo Bicknell <bicknell@ufp.org>, Drew Eckhardt <drew@PoohSticks.ORG>, hackers@FreeBSD.ORG
Subject:   Re: eXperimental bandwidth delay product code (was Re: Network performance tuning.)
Message-ID:  <Pine.GSO.4.21.0107161035530.2151-100000@rac2.wam.umd.edu>
In-Reply-To: <200107161420.QAA48911@info.iet.unipi.it>

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I have been testing this over a very slow (barely ever over 24000 bps due
to a crappy phone line) dial-up link, and as expected, over an idle line
there is no difference (typing in an interactive ssh session seems a
little quicker, but that could just be me). The gain comes when someone is
downloading over the link and I try to type in an interactive ssh
session. (I'm sharing the link with 1 other computer). Without the sysctl
turned on typing in the "interactive" session results in a 10-15 second
wait before anything appears on the screen; but with the sysctl turned on
the wait is 2-3 seconds. I'd say that's pretty good work :-)

Ken

On Mon, 16 Jul 2001, Luigi Rizzo wrote:

> > Cool!  We were just commenting that it's too bad dummynet/ALTQ really
> > couldn't help the interactive response for us dial-up users.  Anyway, I
> 
> i haven't seen the beginning of the thread but surely both altq
> and dummynet can help, with the CBQ/WFQ support.
> 
> In the case of dummynet, you can pace incoming traffic as well,
> at your endpoint. This means you act after the bottleneck,
> but the effect is that this way
> you will delay acks, and so slow down the connection eating a lot of
> bandwidth, and in the steady state this keeps the queue very
> short even before the bottleneck.
> Much like what products like packeteer do.
> 
> 	cheers
> 	luigi
> 
> > just tried this on my dial-up connection on a fresh -STABLE but don't
> > really notice any appreciable difference.
> > 
> > net.inet.tcp.tcp_send_dynamic_enable: 1
> > net.inet.tcp.tcp_send_dynamic_min: 1024 (tried it with default 4096 too)
> > 
> > My ssh response is still about 3 or 4 seconds behind my typing.  What
> > should a dial-up user expect?
> > 
> > Thanks!
> > 
> > Tim
> > 
> > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > with "unsubscribe freebsd-hackers" in the body of the message
> > 
> 
> 
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> 


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